Method of locating knocks in explosive engines



E. A. HAMMl-:TT

METHOD OF LOCATING KNOCKS IN EXPLOSIVE ENGINES Filed March ll0 Y JNVENTo/e H-.Hammef A TTF/v Patented Ang. le, i923.

rattan ELBERT A. HETT, F KANSAS CITY, MISSOURI.

METHOD 0F LOCATING KNOCKS IN EXPLOSI'VE ENGINES.

Application led March 10, 1919.

To all whom. it may concern Be it known that I, ELBERT A. HAMMETT,

a citizen of the United States, residing at Kansas City, in the county of Jackson and State of Missouri, have invented certain new .and useful Improvements in Methods of Locating Knocks in Explosive Engines; and l do declare the following to be a full, cleara and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same, reference being had to the accompanying drawings, and to the letters and igures of reference marked thereon, which form a part of this specification.

This invention relates to a method of locating knocks in explosive engines and the like.

Sao-called knocks7 that is, loose parts in the engines, are indicated by an apparent pounding or jerky motions at the ends of the strokes of the engine piston, and the objections are well known to those skilledA in the explosive engine art.-

rl`he knocks are generally caused by loose connecting rods, loose wrist pins, looseness in the main bearings or piston Slap, but the particular Seat of trouble is diticult to determine from the sound of the engine. This is due in part to the fact that during the operation of the engine there is considerable diverting noise, due to the clacking of valves, contact of the cams, explosion in cylinders other than the one in which the diiiculty arises and the noise caused by the operating parts.`v

I have found that the diculty may be readily located by stoppingthe engine and then turningthe piston crank topractically dead center on the compression stroke just prior to firing, so that both the inlet valve and the exhaust valve will be seated, and then varying the pressure in the compression cylinder from an external source so that any looseness in the piston, piston rings, wrist pins, main bearings, connecting rods, or leakage in the valves may be determined in any particular cylinder, it being necessary to vary the pressure in each cylinder separately to test the correctness of the adjustments or determine their deiciencies, but this can be done While the engine is at rest so there may be no diverting noises and that any test may be locally made for a particular cylinder, as will be presently explained. v

serial No. 281,@94.

The igure in the drawing is a fragmentary perspective View of a known type of engine to which a device is attached for carrying out my method.

Referring now to the me'rals of referencedrawings by nu- 1 designates engine case to which is connected the usual cylinder 2 piston 3, and connecting ro (provided with a l1, wrist pin 5,

crank shaft 6, inlet valve 7, exhaust valve 8, and such other appurtenances as are common to gas engines. 'llhe cylinder head 9 is provided with the usual spark plug opening 10 into which may be screwed a nipple 11 of a pump cylinder 12, provi ded with a piston 13 operated by a pump rod 14.

When it is desired to locate the cause of a knock the operator removes the spark plug and screws the nipple 11 of the pump 12 into the opening 10 as shown, whereupon the piston 13 may be ope rated to vary the pressure in the combustion-chamber 15 by creating a vacuum or by sure, 1t being desirable,

introducing presas heretofore ex- 'so plained, to first crank the piston to a dead center position or to the pression stroke so that bo are seated. lic' the piston ward the cylinder head and there is an esend of itslcomth valves 7 and 8 13 is pushed tooi'air is at either of the valve seats, it will be apparent that the 'valve need grinding. H there i 9o seats or 'the valve s any loose movement of the piston there will be evidence of Vlooseness in the connecting rod and wristpin. An upward pull on the piston 13 may Cause a 410059 IIIOVVGIDGII) 0 f the piston, may

indicate leakage through the piston ring or may indicate looseness in the bearings or wrist in.

lf t e downward stroke of thepiston is strongly opposed by the compression in the compression chamber, an movement of the piston d' if the upward is seriously opposed by the suction therein, there is evidence that that particular cylinder needs no attention as the rings and valves are tight and that no movement exists for the rings, the plston or the wrist pins. rlhe investigator then unscrews the .nipple inserts the spark plug and proceeds to th cylinder and repeats the o knock is located.

e next 11o peration until the.W

The advantage of the above method will be apparent when it is considered that a knock may only occur in one cylinder of vwith almost positive assurance that the trouble has been properly diagnosed and corrected.

Having described my invention, what I claim as new therein and desire to secure by Letters-Patent is -1. The method of locating knocks in explosive engines, which consists in alternately raising and lowering the pressure in the explosion chamber of the engine while the intake valve and exhaust valve are seated.

- messi? 2. The method of locating knocks in explosive engines, which consists in raising the pressure in the explosion chamber of the engine by pumping air into the same from an external source, while the intake and exhaust valves are closed and the piston is substantially on dead center.

3. The method of locating knocks in explosive engines, which cons1sts in connecting a pump to the explosion cylinder and operating the pump to vary the pressure in the cylinder.

4. A method of locating a loose piston connection in one cylinder of an internal combustion engine, the method consisting in alternately raising and lowering the pressure of a duid within the cylinder, while the engine is at rest.

In testimony whereof li aiiix m si; ature.

ELBER'F A. i. "l 

